lol. your in the for sale section...lol. I will move it.
is really a preference by the owner. For cold weather areas we usually recommend 80-90 weight hypoid fluid
For the warm /Hot weather areas a thicker 85/140 weight we recommend.
Synthetic is great BUT in the limited slip applications with Steel clutches synthetic can be counter active to what you want a posi/ limited slip to do, which is LOCK UP and give that 2 tire hook up.
So for Limited slip application on aftermarket unit Eaton and Auburn recommend NON Synthetic fluid. Meaning use natural Mineral base out of the ground oil or call conventional hypoid gear oil.
Open, non posi, True Trac and Power Traxs units can all use synthetic fluid with out conflicting mechanic and warranty issues.
- we DO NOT sway a brand... instead we concentrate more on having the rear completely filled to the correct level ...this is a much more critical area as with out the right fluid level the oil viscosity will beak down quicker and cause failure to carrier and axle bearing systems.
Check your oil level at least twice a season of driving as long as there are NO leak issues
Hope this answer your question
J D Race